Method and apparatus for surface grinding metal strip



LE ROY R. VALETTE ETAL I 2,759,301

16 Sheets-Sheet 1 EDP Ob hbQ mr 1% I I i I i @W Aug. 21, 1956 METHOD ANDAPPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16, 1953 g 1 LEROY R. VALETTE ET AL 9,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP 1s sheet's-shet 2Filed July 16, 1955 m-- O Maw g- 1, 1956 LE ROY R. VALETTE ETAL2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1953 16 Sheets-Sheet 3 mm IQUZb INVENTORS. LE/Po y/P. VALETTE BY VV/LLIAM C. SAFFOED.

low/M N ATTORNEYS 1956 LE ROY R. VALETTE ETAL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1953 16 Sheets-Sheet 4 INVENTORS.

L: w E VA Len-TE, By VV/LL/AM C. SAFFOED.

lbw/a4. QM

A g- 1956 LE ROY R. VALETTE EI'AL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1953 16 Sheets-Sheet 6 lumullul l m INVENTORS. LEPoY 1?. l ALETTE.

Vl/ILL/AM c.5AFFD/PD. zmmgzm METHOD AND APPARATUS FOR SURFACE GRINDINGMETAL STRIP Filed July 16, 1955 Aug. 21, 1956 LE ROY R. VALETTE ETAL 16Sheets-Sheet 7 1, 1956 LE ROY R. VALETTE arm. 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1953 mmvfozgs.

l6 Sheets-Sheet 8 1/ 111/ I II 1 1 WWW ATTO/YNf/i.

1, 1956 LE ROY R. VALETTE ETAL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1955 16 Sheets-Sheet 9 INVENTORS. L: For A. Mqusrrzz. BY M/ILL/AMCSAFro/w.

Aug. 21, 1956 LE ROY R. VALETTE EIAL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP l6 Sheets-Sheet 10Filed July 16, 1953 LJI v:

INVENTORS Ls-fior 1P. l/ALETTE. BY W11. L 1AM C. SAFFORO.

WWW

A TTORA/[Vi Aug. 21. 1956 1.1-: ROY R. V ALETTE EI'AL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July 16,1953 16 Sheets-Sheet 11 IN VEN TORSJ Lsfiar 1?. Vmsrrs. M/ILLIA M(ISA/FORD.

MMYM

AWE/V5715.

Aug. 21, 1956 LE ROY R. VALETTE EI'AL 2,759,301

METHOD AND APPARATUS FOR SURFACE GRINDING METAL STRIP Filed July- 16,1953 l6 Sheets-Sheet l2 INVENTORSI :Por R. l/ALETTE. BY WILL/AM CSnrmea.

I M M ATTORNEYS.

Aug. 21, 1956 LE ROY R. VALETTE EAL METHOD AND APPARATUS FOR SURFACEGRINDING METAL STRIP Filed July 16, 1953 16 Sheets-Sheet l5 Ls .WLEfrE.BY VI/ILLIAM CYSxu-meo.

MMEM

ATTORNEYS.

Aug. 21, 1956 LE ROY R. VALETTE ETAL METHOD AND APPARATUS FOR SURFACEGRINDING METAL-STRIP Filed July 16, 1953 I 16 Sheet's-S'net l4 NewINVENTORS. is For?! VALE-T11: BY VV/LL I A M C. SA rroeo.

ATTORNEYS.

METAL STRIP l6 Sheets-Sheet 15 LE ROY R. VALETTE ETAL METHOD ANDAPPARATUS FOR SURFACE GRINDING Aug. 21, 1956 Filed July 16, 1953 IN V ENTOR-5'. VAL ETTE LIA M C.5Ar'raea.

ATTORNEYS.

LE For P. m

MMKM

United States Patent -METHOD AND APPARATUS FOR SURFACE GRINDIN G lVLETAL"STRIP Le Roy R. Valette, Pittsburgh, and William 'C. Safiord, Industry,Pa., assignors to Crucible Steel Company of America, Pittsburgh, Pa., acorporation of New Jersey Application July 16, 1953, Serial No. 368,374

16 Claims. (Cl. 515) This invention pertains to improvements in grindingapparatus for the surface grinding and removal of surface defects frommetal strip, such, for example, as long lengths of steel strip ofsufiicient thinness to permit of coiling onto reels, and in widths whichmay vary from a few inches up to 50 or 60" or more.

In the hot rolling of a metal breakdown into long lengths of relativelythin strip, surface defects, such as slivers, are often produced as aresult of the rolling operation. Such defects are not removed bysubsequent pickling and cold rolling, but are carried through as surfacedefects of the finished cold rolled product. In the pro ductionparticularly of high grade alloy steel strip, such, for example, as the18-8 chromium-nickel or the straight chromium staindless varieties, suchas are employed for trim in the automotive, building industries, etc.,it is essential that the cold rolled and finished product have a smooth,unmarred surface of high luster, entirely free from all surface defects.It is accordingly frequently necessary in order to obtain a surface ofthis character in the finished cold rolled product, that all surfaceportions of the hot rolled strip be subjected to roughing and finishinggrinds, prior to finish cold rolling.

Grinding units heretofore employed for such purposes have in generalbeen of the single-stand variety in which the strip is fed from a payoffreel between a pair of driven rolls, about one of which an abrading beltpasses, the opposite roll serving as a backing up roll, thus to surfacegrind one side of the strip, which passes thence onto a windup reel.Grinding units of this character are expensive and cumbersome inoperation due to the fact that each pass through the grinding unitrequires unreeling and reeling the strip, and transporting the reeledunit back to the payoff reel for each successive pass through thegrinder. Frequently a half dozen such passes are required properly tosurface grind and finish each side of the strip, or a total ofapproximately a dozen or so passes in all.

In contrast to the above, the improved grinding apparatus of the presentinvention comprises a multiplicity of grinding units arranged seriatim,through which the strip is progressively and successively fed, from apayoff reel disposed at the entrance to the multi-stand grinding assembly and thence onto a coiling reel at the delivery end thereof. inaccordance with various aspects of the invention, the grinding units maybe of the conventional abrading belt variety or may comprise a series ofabrading rolls or a combination of abrading rolls and abrading belts,and may be arranged to surface grind one or both sides of the strip asit passes through the multi-stand grinding assembly aforesaid.

The initial abrading stands of the sequence may thus be arranged toprovide roughing grinds and the remainder of the sequence, finishinggrinds of varying degrees of impression, so that in a single passthrough the multi-stand sequence, the strip is both rough and finishground, and thus emerges ready for pickling and cold rolling. If bothsides are surface ground concurrently, the strip need be unreeled andreeled but once; while if only one surface at a time is ground, only twounreeling and reeling operations are involved.

By the provision of a sufficient number of the grinding stands insequence, for example, six in accordance with the preferred embodimentof the present invention, the abrading elements in certain of the standsmay normally be disengaged from the strip while the remainder aregrinding, so that in the event one of the stands which is effecting thegrinding requires disengagement for repairs or for changing an abradingbelt, one of the normally idle stands may be engaged during the interim,thus to assure uniformity in the grinding operation throughout the entire strip length. The apparatus of the invention thus provides extremeflexibility of operation in this respect, and also in the respect thatone, two or more or all stands may be caused to engage the strip duringa given grinding operation, depending on the extent of surface grind--ing required for that particular length.

Each of the grinding units, in the preferred embodiment thereof,comprises in tandem, a pair of entry pinch rolls, an abrading roll orcontact roll carrying an abrading belt, together with an associatedpressure roll, and an exit hold-down roll, these rolls being positionedfor rotation about horizontal axes. To facilitate the threading of theleading strip end of a coil through the grinding unit, one of the pinchrolls is mounted for retraction with respect to its opposed pinch roll;and likewise the pressure roll is mounted for retraction with respect toits opposed abrading roll. After the strip end is threaded through thegrinding unit, these rolls are advanced into their operative positionsfor resiliently pressing the strip against the opposed pinch andabrading rolls, respectively. In the preferred embodiment, thisretraction and advance ment of the pinch and pressure rolls is rapidlyeffected by means of hydraulic cylinder and piston assemblies.

Also in the preferred embodiment the pressure and abrading rolls aredisposed slightly above the pass line of the entry pinch and exithold-down rolls, in order arcuately to flex the strip over the pressureroll, thus to provide a substantially tangential area of contact betweenthe abrading roll and the strip surface contiguous thereto, thus toassure uniform surface grinding of all portions of the strip.

Fine or micrometer adjustments are provided in the mounting for thepressure roll of each grinding unit, for adjusting the same relative tothe associated abrading roll in accordance with the thickness of stripbeing ground, and also for purposes of axially aligning the pressureroll, in absolute parallelism with the associated grinding roll. Variousnovel features are embodied in the mounting and adjustments of thepressure roll, as will more fully appear hereinafter in the detaileddescription relative thereto.

The entry pinch rolls of each grinding unit are further provided withdisengageable braking means, for applying braking action thereto as thetrailing end of a coil of strip being ground, passes off the payoff reeland successively thence through the grinding units, the so-braked pinchrolls serving thus to maintain tension on the strip between thesuccessive grinding units and the windup or recoiling reel.

In the preferred embodiment there is also interposed between the payoffreel and the first grinding unit of the sequence, a levelling unit ofnovel construction, comprising a series of lower rolls, having opposedthereto in intercalated or staggered relation, a series of upper rolls,together with a pair of entry pinch rolls and a pair of entry guiderolls, the latter being rotatable about the vertical axes for centeringthe strip in the leveller. The opposed intercalated rolls serve tostraighten the strip as it is fed therethrough. The upper levellingrolls are ar- Patented Aug. 21, 1956 ranged to beindividually elevatedand depressed relative to their associated lower rolls, and the same istrue of the upper entry pinch roll. The levelling and pinch rolls arearranged to be motor driven. For feeding an advancing strip end throughthe leveller and into the first grinding unit, the upper pinch andleveling rolls are depressed and all rolls are driven. After the stripis fed completely through the apparatus from the payoff reel onto therecoiling reel, the upper rolls of the leveler are either elevated awayfrom the strip, or are thereafter arranged to function merely as idlerrolls, since the power applied for driving the recoiling reel sufficesto feed or pull the strip through the entire grinding line from thepayofi? reel, and since also the resulting tension thus applied to thestrip thereafter suffices for straightening or flattening purposes. Forthus controlling the tension on the strip, the payoff reel motor isarranged for optional driving or regenerative braking, and isregeneratively braked after the leading strip end has been 'fed onto therecoiling reel and driving power applied thereto.

Other important features of the invention reside in special provisionsfor safety and operation and adjustment of the several units and forindividual and integrated driving and control means for the severalunits, whereby efficiency and safety are greatly enhanced.

Further objects and advantages of the invention will more fully appearfrom the following description taken in connection with the accompanyingdrawings which show, by way of example, a presently preferred embodimentand certain modifications of the invention.

Referring to the-accompanying drawings inwhich the same referencecharacters indicate the's'ame parts in the various views:

Figures 1 and 2 jointly constitute a somewhat diagrammatic view of oneembodiment'of the invention, showing the general arrangement of certainfeatures 'of a grinding line assembly in side elevation and associatedmain control panel shown in plan view;

Fig. 3 isa side elevational View of the payotf (unit A) or reel uncoilerat the input 'or entry e'ndof the machine;

'Fig. 4 is an end elevational view'of'the unit shown in Fig. 3, asviewed from the strip reel end;

5 is a cross-sectional view taken at line S'-Sof Fig. 3;

Fig. 6 is a cross-sectional view taken at line 6- 6 of i Fig. f7is asomewhatdiagrammatic view showing the end of the strip passing from thecoil of strip to the pinch rolls of the leveller;

Fig. 8 is a plan view and Fig. 9 '21 front end' elevation of thelevellingunit B of theFigures 1- 2 apparatus;

'Fig. 10 is a longitudinal sectional elevation of line 10- 10 of Fig. 8;v

Fig. 11 is an enlarged fragmentary side' elevationof the Figures 8 and 9apparatus, as viewed from the left in Fig. 8;

Fig. 11a is a cross-sectional view taken at =-line 11a11a of Fig. 11showing further'details;

Fig. 12 is a plan view of one of the limit switches shown in Fig. 11;

Fig. 13 is a perspective view of one of the cams and mount of the Figure11 limit switches;

Fig. 14 is a side elevation of one'of theg'rin ding units, such as C1,of Figure 1 with the housing'broken away to show the interior mechanism;while"Fig. '15 is a front elevation of the Figure 14 apparatus, againwith'the housing in section to show the interior'con'struetion;

Fig. 16"is asectional plan as' taken substantially at 16-16of Fig. 14;

Fig. 17 is a sectional plan view as'taken substantially at 17-17 ofFigure while Fig. 18 is a fragmentary end section as taken substantiallyat 18 18 of Fig. 17;

Fig. 19 is a longitudinal elevation ofthe'furne and dust removal systemfor the grinding units C1-C6 forming ll part of the apparatus shown inFigures l-2; Fig. 20 is a sectional elevational view taken at 20-20 ofFig. 19, and Fig. 21 is a fragmentary plan view of one of the fume ductsof the apparatus shown in Fig. 19, for removing fumes and dust from oneof the grinding units;

Fig. 22 is a side elevational view of the windup (unit F) or recoiler atthe output end of the machine;

Fig. 23 is an end elevational view of the unit shown in Fig. 22 asviewed from the drive and braking end;

Fig. 24 is a fragmentary side elevational view showing certain otherfeatures of said unit;

Figs. 25-28, inclusive, are somewhat diagrammatic side elevational viewsshowing various alternative modifications of the grinding unitassemblies according to the invention;

Fig. 29 is a diagrammatic layout of the hydraulic control system of theapparatus, for actuating various hydraulic .piston and cylinderassemblies employed in the apparatus as described below; and

Fig. 30 is a corresponding diagrammatic layout of the direct-currentelectric control system of the apparatus, for controlling the variousdirect-current, energized motors, solenoids, etc., asdescribed-below.

GENERAL DESCRIPTION Referring now to the drawings and more particularlyto Figs. 1 and 2: the apparatus therein comprises in general a payoffreel unit A, a leveller unit B, a sequence of six-grinding unitsindividually designated C1C6, inclusive, arranged seriatim or :in tandemas shown, a scrubber D, a wiper unit'E and a windup reel unit F. Inaddition to these main units there are provided suitable electric,hydraulic and pneumatic motors, together with controls therefor groupedat stations located at convenient positions adjacent theentry end of theapparatus, 'at each grinding unit and at the deliveryend, all beingintegrated to facilitate operation. The control stations are disposed asfollows: Main stations I and II are located adjacent the delivery andentryends, respectively, and a series of stations III are locatedadjacent respective of thegrinder units C1-C6, inclusive.

The payoff reel unit A comprises apayoft reel .22, for mounting a coilof-strip 23'on'the'rcel shaft, which is coupledto a motor Zlaoptionallyoperated as a motor or draggenerator, and thus adapted'eithcr todrive'or brake'the shaft. A blocker hoist 24-is provided. adjacent thepayoff "reel shaft to facilitate"mountingit-hecoil..23 on the reel shaftas explained below.

Next in the sequenceisthe strip lcveller unit B-whieh comprises a: guideroll-29, a pair of spaced apart vertical centering rolls 30, an upperseries 33 and a lower series 32 of'levelling rolls'between which thestrip S'passes for straighteningzpurposes. These rollsare arranged tobe'driven or'idled as desired at various-stages of-thc grindingoperation, having associated therewith'for: such purposes adrive motor'el coupled to the rolls. Likewise, the upper series of ro'lls 33 aremounted in bearing blocks,

vertically displaceable in: guidewaysnbynmeansa 'of suitable electricmotors43a to behe-reinafter described, for raising the upper rolls offthe'strip' once it has been fed through the assembly 'line. Drivenpinch= rolls 55-56 aref-provided for feeding the strip to the levellingrolls-and are separable by fluid motorsSS to permit free passage.

Next in the sequence is the series of grinding units C1-C6, each ofwhich comprises in substance a :pair' of entrance pinchrolls, suchas86'87,"between which the strip isfed, and the upper 'roll beingprovide'dwith fluid actuated brake means to producea dragon the strip, and thelower roll being retractable, at certain conditions of operation; asabove' mentioned. Beyond the pinch rolls, in the direction of the strippath, area pair of rolls 89 and 92, one of 'which'comprises' an abradingroll'or an abrading belt contact roll, su'ch as"92, the opposite roll 89functioning as a backing up or, pressure roll. In certain modificationsof the invention, the upper roll is the abrading roll or abrading beltcontact roll, while the lower or pressure roll is arranged for verticaldisplacement toward and away from the strip, thus to be elevated andengage the strip during grinding, and to be dropped well below the strippass line to facilitate feeding the leading strip end of a new coilthrough the grinding unit. At the exit of each grinding unit there ismounted a holddown roll, such as 91), the function of which inconjunction with the entrance pinch rolls 36-37 is to flex the striparcuately over the backing up roll, thus to provide a tangential line ofcontact transversely of the strip between the strip surface being groundand the upper abrading contact roll engaging the same for grindingpurposes.

The strip on emerging from the last of the grinding units, e. g., C5,passes thence through a scrubber unit D for removing grit, sludge,grinding compounds and the like from the strip, and thence through awiper unit E for removing excess scrubbing fluid, from whence the strippasses onto a driven windup reel 184 on which the ground strip S iswound into a coil 186.

PAYOFF UNIT A Referring now to Figs. 3-6, inclusive, the payoff reelunit A comprises a main frame 21 and a motor-drag generator 21a suitablyconnected through a reduction gear train Zib-Zic to a reel shaft 22a fordriving or braking a payoff reel 22. The payoff reel is of theconventional expansible segment type actuated by a conventionalhydraulic mechanism 22be, inc, for expanding and gripping the coil 23 ofstrip S to be surface ground. Adjacent the payoff reel there is provided(Fig. 1) a coil hoist 24 having mounted thereon a pair of hoist blockerrolls 24a, on which the coil 23 of strip S is rotatably supportedpreparatory to mounting 011 the reel 22. The coil hoist is raised andlowered by conventional hydraulic ram and cylinder means mounted belowthe floor line as described below. Adjacent the coil hoist is aninclined ramp 26 provided with elevatable floor chocks (not shown) forrolling the strip coil 23 onto the hoist blocker rolls. By aconventional hydraulic means, such as cylinders 25, Figs. 4 and 6, andpistons, as at 25a, operating therein as shown, the reel 22 can be movedaxially in and out to receive the coil 23 from the hoist 24, and to linethe coil up with the grinding line equipment. To this end the entirecoiler assembly is slidably mounted on wear plates. as at 25b. one oneach side, and is axially displaced in and out by oil pressure anddischarge lines interchangeably connectible through a 4-way valve, asexplained below, to the opposite end, respectively, of cylinders 25, 25,thus to displace these cylinders relative to their associated pistons,which latter are pin connected, as at 250, to fixed supports, as at 25d.

An important safety feature of the invention embodied in this unit isthe provision of an arcuate arm 27 (Figs. 3 and 4) which extends in adirection transverse the axis of a coil 23 and disposed intermediate itsends. The arm 27 comprises side plates between which are pivotallymounted a main roller 27a adjacent its forward end, intermediate rollers27b and 27c in spaced relation along the arm and a pair of rollers 27don a rear extremity disposed beyond the axis of a torque shaft 27:? toone end of which the arm is fixed. The rollers 27a27d, inclusive, havetheir axes generally parallel to the axis of reel 22 and are spacedapart along an arcuate path preferably having a larger radius than theradius of coil 23. The rollers are so disposed that when roller 27aengages coil 23 the other rollers are progressively spaced from saidcoil while the strip is being fed forward and serve to res-train outwardmovement of a loose strip end. The shaft 27c is suitably journaled onthe frame 21 and adjacent its opposite end carries fixed thereto a crankarm 27] to the outer end of which is pivotally connected a piston rod27g of a pneumatic motor designated 27h. This motor is operated by asuitable control valve, to be hereinafter referred to, convenientlypositioned at the entry end.

LEVELER UNIT 3 From the coil 23 (Fig. 2) the leading end of the strip Sthereof is fed to the levellcr unit B. The latter comprises, as shown inFigs. 7-10, inclusive, an entry guide roll 2-9, disposed as shown, forengaging the strip S when the coil 23 becomes reduced sufficiently indiameter during the unreeling operation. At the entrance of the levellerthere is also provided a pair of oppositely disposed and verticallyarranged guide rolls (Fig. 9), such as 38', for centering the striptransversely in the leveller.

Guide rolls 30 may be adjustably spaced, in accordance with the stripwidth, and may also be adjusted right or left as viewed in Fig. 9, atconstant spacing. To this end, the rolls are journaled to bearingblocks, such as 31a, which in turn are secured to yokes, such as 31b,these yokes in turn being suitably bored as at 310, for slidablemounting on guide bars 31d, 31e. The yokes are also tapped as at 31f,for threaded engagement with adjusting shafts 31g and 31h, respectively.These shafts are threaded in opposite directions, as shown, shaft 31g infact constituting a sleeve member rotatable on an extension of shaft 31hextending therethrough as at 311. Keyed to shaft Zili is a hand wheel31k while keyed to shaft 31g is a second hand wheel 31m. Thus, if thehand wheels 31k and 31m are rotated concurrently in the same direction,the guide rolls 30 will be displaced toward or away from each other,whereas if the hand wheels are rotated in opposite directions atconstant speed, the guide rolls will be adjusted right or left atconstant spacing, as viewed in Fig. 9.

The leveller B comprises in addition to the elements aforesaid (Fig.10), a set 32 of three driven bottom rolls 32a, 32b and 32c journaled attheir opposite ends in oppositely disposed stationary bearing blocks 32dand File (Figs. 10 and i1), and a set 33 of two driven top rolls 33a and33b. The roller 33a is journaled in oppositely disposed end blocks (Fig.11a) 34a-34a and the roller 33b is similarly journaled in correspondingblocks Mfr-34b. The blocks 34a34ib at one end of the rollers are heldtogether in a horizontal direction but permitted relative verticalmovement by means of a dovetail connection designated 35 and the blocks34a-34b are similarly held together by a like connection 35. Theconnected blocks 34a34b and 34a'34b' are supported in aligned positionand vertically adjustable in oppositely disposed end guides 36a36b and36a36b', respectively. The rollers 33a and 33b are individually movableup or down by mechanism now to be described.

The bearing blocks 34a-34a are adjustably supported by respective shafts3737' (Figs. 10 and 11a) having threaded portions engaged in cooperatingthreaded bores provided in worm wheels, such as 39, which are in drivenengagement with worms, such as 39a, secured to a worm shaft 41. The wormwheels 39a and shaft 41 are suitably journaled in stationary end frames42a and 4211. Similarly, the blocks 34b34b' are adjustably supported onshafts 3838 cooperatively adjustable by means of worm wheels, such as a,driven by worms, such as 39a, secured to worm shaft 42. The worm shafts42 and 41 are respectively driven by motors 43a and 43b (Figs. 8 and 10)to which they are suitably drivingly connected as by means of chain andsprocket drives 43d43f and 430-43e, respectively.

In order to facilitate the control of the raising and lowering of thebearing blocks 34a and 34b, means are provided for simultaneouslyenergizing the motors 43a and 43b to raise such blocks, the latter beingautomatically stopped under the influence of pairs of limit-stopswitches 44 and 45 (Fig. 11). The switches 44 and 45 are respectivelyprovided with switch levers 44a and 4501 which carry pivotally mountedon their outer ends cam rollers 44b and 45b in the path of movement ofcam members 46 and 47, respectively, which are secured to the bearingblocks 34a and 34b, respectively. The cams 46 and 47, for example, areof the wedge variety and are ver- 7 tically adjustable by suitablescrews, whereby the actuation of switches 44a and 44b may be properlytimed.

Conversely, motors 43a and 431) are automatically stopped by thedownward movement of the bearing blocks 34a and 34b, respectively, byanalogous mechanism including switches 40 and 49 having respectivelyswitch arms 48a and 4911, cam rollers 43b and 49b and cooperating cams50 and 51, respectively. Such cams are likewise adjustable verticallyfor timing the actuation of the switches 43 and 49.

As is well shown in Figs. 10. 11 and 13, the earns 46 and 50 areadjustably mounted on a bracket 52 which is rigidly secured to thebearing block 34a for movement therewith and there being adjustmentscrews 53 and 54 for fixing the position of the cam 50 upon such bracketand similar adjustment means for cam 46. In a similar manner the cams 47and 51 are mounted on the bearing block 34b.

In addition to the aforementioned primary and secondary sets of levellerroll-s, there are also employed a pair of leveller pinch rolls (Figs. 7,8 and 9), such as 55 and 56. The former is preferably mounted forrotation upon a fixed axis but the latter can be raised or lowered. Thetop pinch roll 56 is mounted in suitable bearing blocks, such as 5757.The latter can be raised or lowered by means of a power cylinder, as at58, which may be actuated by any suitable fluid medium. Preferably thereare two such cylinders 53, one for each side of the apparatus.

The sets of rolls 32 and 33 and the pinch rolls 55-56 of the levellerunit are driven by means which will appear more fully below, for feedingthe advancing strip end into the first grinder. When the strip gets intocoiling position upon a winding reel, to appear hereinafter, the upperrolls are lifted to the position shown in Fig. 11 so as to clear thestrip. The rolls of the leveller may or may not be continuously driven.Either the top and/or the bottom rolls can be power driven.

in the present embodiment the rollers of the leveller B (Fig. l) are alldriven by an electric motor 62 (Figs. 3

and 4) which is connected by a suitable gear box 62a and shaft connector621) to a reduction gear box 620 from which splined and universaljointed shafts 62a, 62a and 62 serve to supply driving power to thethree shafts 32a, 32b and 326, and similarly shafts 62g and 62h and 62iand 62 serve to drive the upper leveller rolls 33a and 33b and the pinchrolls 55--56, respectively. An electric motor 62l drives suitablelubrication means for supplying lubricant to the drive train of motor62.

GRINDING (UNITS C1-C6) A typical grinding unit C1 is shown in Figs. 14l8and will now be described. The strip is first directed between a pair ofsuperimposed entry pinch rolls 86, 87. the upper of which is mounted instationary bearing blocks, and the lower of which can be raised orlowered by a pair of suitable power cylinders, one for each end of roll87, one of which cylinders is shown as at 88, actuated, for example, bypneumatic or hydraulic fluid. Power cylinders 88 communicate thrust totheir respective bearing blocks 87a of roll 87 via piston rods 88a. Inthe modification shown in the drawings, no drive is applied to thesepinch rolls. The web passes thence convexly over a bottom pressure roll89, the top surface of which is somewhat above the bite of the pinchrolls 86, 87. Thence the web 27 is passed beneath a hold-down roll 90,the rolls 86, 87, 89 and 90 being so positioned to cause the web 27 totravel convexly over the bottom pressure roll 89, thereby to present aconvex surface substantially tangential to the opposed abrading elementcomprising in the modification, an endless belt 91 which is mounted totravel in a well known and conventional manner, upon three rollsconsisting of a contact roll 92 which is opposed to and in verticalalignment with the bottom pressure roll 89, an idler roll 93 at the topof the three rolls, and a belt tension and takeup roll 94 which, in theform shown, is mounted upon one arm of a bell crank 95, the latter beingcentrally pivoted at 96. The outer extremity of the opposite arm 95athereof is pivotally connected as at 99, to a piston 98, operating in apneumatic cylinder, to thereby provide for automatic belt tensioning bypneumatic pressure continuously applied to the cylinder and thus to thepiston. (Selective belt oscillation is provided as by an oscillatingcylinder 80 and oscillation adjustment 81.) Thus, the danger ofstretching the belt edges is substantially eliminated thereby addinggreatly to the belt life.

The contact roll 92 preferably consists of a metal core having a rubberor rubber-like covering. The other rolls 93, 94 may be similarly coveredif desired, but in the form shown are not.

In order to assist in controlling the tension of the strip 5, the pinchrolls 86, 87 are provided with suitable brake means in the form showncomprising a friction brake having a brake shoe for the top roll 86, asat 100, and a shoe for the bottom roll, as at 101. Suitablehydraulically actuated means may be employed for controlling the pinchroll braking means comprising, for example, a power cylinder and pistondevice, as at 102, having a piston rod 103, which pivotally engages abrake arm 104. The latter is operatively connected with theaforementioned brake shoes and 101. The pinch roll brakes are appliedwhen the trailing end of the strip or web is about to clear the payoffreel. The tension upon the web can thus thereafter be maintained untilthe trailing end passes the last grinder. Two such braking means, onefor each extremity of roll 86, may be employed.

A four-way valve 97a is provided for controlling the actuation of thepower cylinder 97. As will be more particularly pointed out hereinafter,suitable manually controlled valves are provided respectively forcontrolling the braking of the top pinch roll and also for raising andlowering the bottom pinch roll; pressure meters are provided forindicating the pressure between the pinch rolls 86, 87 and also thepressure upon the pinch roll braking means; a pressure meter is providedfor indicating the pressure on the bottom pressure roll 89.

The bottom pressure roll 89 is mounted for angular movement about apivot, as at (Fig. 14). Means are provided for quickly disengaging thebottom pressure roll 89 from the strips comprising, a pair of oppositelydisposed arms 106 pivoted on the aforementioned pivot point 105, saidarms supporting a pair of bearing blocks 1.07 for supporting oppositeextremities of the bottom pressure roll 89. Quick disengagement of therolls 89, 92 is obtained by means of a knee type toggle linkage,indicated generally at 108 (Fig. 14) and comprising upper and lowerlinks 109 and 110, there being a pair 109, 110 for each side of theapparatus. Referring to Fig. 15, it is seen that the link 109 comprisestwo parallel side plates 109a and 1091; of equal lengths secured attheir extremities by pins which hold the same rigidly in spacedrelationship. The upper extremities of the links 109 are pivotallysecured, as at 111, to a yoke 107a which supports the bearing block 107.The lower extremities of links 109 are pivotally associated at the kneeby means of pins, such as 112, with which the connection is made withthe lower links 110 Whose lower ends are pivotally secured, as at 113,to eccentrics 114 (Fig. 18). The angular movement of such eccentricsraise or lower by equal amounts opposite extremities of the bottompressure roll 89 by means of the linkage 108.

The eccentrics 114 preferably are formed integrally, one on each end ofshaft 117 which is drivingly connected to a geared electric motor 118(Fig. 15) through the intermediary of the following interconnection: Achain and sprocket drive 1180:, a shaft 119, a worm and wheel unit 120,a shaft 121 having therein a universal joint 122, and a second worm andwheel unit 123.

A rapid disengagement of the rolls 89, 92 is effected

1. IN AN APPARATUS FOR SURFACE ABRADING AN ELONGATED STRIP OF METAL, THECOMBINATIION OF: A PAYOFF REEL FOR ROTATIVELY SUPPORTING A COIL OF SAIDSTRIP; MEANS FOR DRIVING SAID PAYOFF REEL TO UNWIND SAID STRIP;LEVELLING MEANS ADJACENT SAID PAYOFF REEL FOR RECEIVING THE LEADINGSTRIP END FROM SAID COIL AND FEEDING SAID STRIP FORWARDLY WHILELEVELLING THE STRIP; A TANDEM ARRANGED SERIES OF GRINDING UNITS FORSUCCESSIVELY RECEIVING SAID LEADING STRIP END; EACH SAID GRINDING UNITINCLUDING IN TANDEM, A PAIR OF ENTRY PINCH ROLLS, A DRIVEN ABRADING ROLLAND OPPOSED PRESSURE ROLL, AND A HOLD-DOWN ROLL, MEANS FOR RETRACTINGSAID PRESSURE ROLL RELATIVE TO SAID ABRADING ROLL